Colorfastness to rubbing, called crocking in American usage, measures how much color rubs off a fabric onto another surface. Poor rubbing fastness shows up as blue marks on a white sofa from new jeans, dark lines on a light bag strap, or color on the inside of a light lining.
How the test works (principle)#
A small square of standard white rubbing cloth is fixed to the finger of a crockmeter. The finger presses the cloth on the fabric specimen with a set force and moves back and forth for a set number of strokes along a set track. The white cloth is then assessed with the grey scale for staining.
The test is run twice:
- Dry rubbing: the rubbing cloth is dry.
- Wet rubbing: the rubbing cloth is wetted to a controlled moisture content before rubbing.
Both are usually tested in the length and width directions. The exact force, number of strokes, finger size, cloth and wetting are defined by the method, such as ISO 105-X12 or AATCC TM8, and must be followed exactly.
Ratings#
The white rubbing cloth is rated from 5 (no staining) to 1 (heavy staining). Wet rubbing is almost always lower than dry, often by one grade or more, because water helps loose dye and pigment move.
| Result | Dry | Wet |
|---|---|---|
| Example, well-cleared light shade | 4-5 | 4 |
| Example, deep indigo denim | 3-4 | 2 |
Required grades come from the buyer's specification and often differ for light and dark shades and for different product types.
What affects rubbing fastness#
Dye on the surface#
Rubbing removes color that is loosely held on the surface: unfixed dye, hydrolysed reactive dye that was not washed off, or ring-dyed yarn surfaces. Thorough wash-off after dyeing is the main defence.
Shade depth#
Deep shades carry more dye and are harder to clear. Black, navy and red in cotton are common problem shades, especially for wet rubbing.
Dye class and fiber#
Indigo on denim is deliberately surface-dyed (ring-dyed), which is why it fades and why denim wet rubbing is typically low. Sulphur blacks also tend to rub off more than well-fixed reactive dyes.
Pigment printing and dyeing#
Pigments sit on the surface held by a binder. Too little binder, poor curing (time or temperature) or a thick print film gives poor rubbing fastness and can also cause print cracking.
Fabric surface and finish#
Brushed, peached or napped surfaces release fibers with color on them. Some softeners reduce friction and improve dry rubbing; others can make wet rubbing worse. Silicone softeners are often used to improve rubbing on dark shades, but check the effect on the whole specification.
Improving rubbing fastness#
| Cause | Action |
|---|---|
| Unfixed dye | Better soaping and rinsing after dyeing; check water hardness and rinse temperature |
| Deep reactive shade | Optimise recipe and fixation; consider a fixing agent where the buyer's chemical rules allow it |
| Pigment print or dye | Correct binder amount; full curing at the recommended temperature and time |
| Surface fibers | Singeing or controlled brushing; review finishing sequence |
| Softener | Choose a softener compatible with rubbing requirements |
Always re-test after a change, because some after-treatments that help rubbing can affect other properties such as shade, hand feel or light fastness.
Common mistakes#
- Testing only dry. Wet rubbing is the usual failure.
- Testing a lab dip instead of bulk. Bulk dyeing and finishing conditions differ.
- Ignoring direction. Some fabrics rub differently in length and width.
- Assuming a care label fixes it. Rubbing happens in wear, not in washing.
See also colorfastness testing for grey scales and other tests, and the poor rubbing fastness defect guide for troubleshooting in production.
Related guides#
- Color fastness to washing: wash fastness, often tested together with rubbing.
- ISO, ASTM and AATCC test methods: rubbing methods by standard.
- List of top 100 denim jeans brands: denim, where rubbing fastness is a constant concern.
- Fabric testing standards and methods: color fastness within the full test program.
- Pantone color guide and its application in textile: color approval before fastness testing.